Add ability to flush FLP HAL batched locations buffer.

Currently GmsCore has to guess how many locations to retrieve
based on requested frequency and then demux the output looking
for timestamps (that aren't monotonically increasing).  This
capability gives GmsCore a more graceful solution.

Change-Id: Ie1d71615f699bc0d3c63f8b80aa7b40b9971cf96
5 files changed